IntroductionCellular respiration is a series of enzyme-mediated
reactions that release the energy from carbohydrates.It begins in the cytosol with glycolysis and is completed within the
mitochondria.Cellular Respiration
can be summarized with the following equation:

Cellular respiration could be measured in
several different ways, but in this experiment oxygen consumption is used.To do this, it uses a number of the physical laws of gases including the
equation, PV = nRT, where P stands for pressure, V for volume, n for the number
of molecules, R for the gas constant, and T for temperature.This law shows the many relationships between these factors and how they
affect each other.

This experiment compares respiration rates
in germinating and non-germinating peas.Germination
is the growth processes of a seed.It
requires a lot of energy to break the seed coat and as it continues to grow this
energy need increases.Respiration
is required to access this energy so as the seed germinates its respiration
rates increase.Non-germinating
seeds, however, are dormant and use very little respiration.Some respiration must occur in order for the seed to live.

HypothesisThe
rate of cellular respiration will be greater in germinating peas than in dry
peas, and temperature will have a direct effect on this rate.

MethodsA room
temperature bath and a 10°C
bath were prepared.A 100-mL
graduated cylinder was filled with 50 mL of water.Then, 25 germinating peas were added and the amount of displaced water
was determined and recorded.The
peas were then removed and placed on a paper towel until needed for Respirometer
1. The graduated cylinder was then refilled with 50 mL of water.25 dry peas were added and beads were added until the volume equaled that
of the germinating peas.The peas
and beads were removed and placed on a paper towel for use in Respirometer 2. After
refilling the graduated cylinder with 50 mL of water, beads were added until the
volume again equaled that of the germinating peas.They were removed and placed in a paper towel for use in Respirometer 3.The above
procedures were repeated to prepare a second set of germinating peas, dry peas
and beads, and beads for use in Respirometers 4, 5, and 6.The respirometers were prepared next by first placing a small wad of
absorbent cotton in the bottom of each respirometer and saturating it with 15%
KOH, being careful not to get any on the sides of the vial.Next, a piece of non-absorbent cotton was placed on top of
the KOH-soaked cotton.The first
set of germinating peas, peas and beads, and beads were added to Respirometers
1, 2, and 3.Then the second set
was added to Respirometers 4, 5, and 6.A masking
tape sling was created for each of the water baths to hold the respirometers out
of the water during equilibration.Respirometers
1, 2, and 3 were placed in the room-temperature bath, and Respirometers 4,5,and
6 were placed in the 10°C
water bath.The respirometers were
allowed to equilibrate for 10 minutes and then were immersed entirely in the
water bath. They were checked for leaks and an initial reading was taken.Then additional readings were taken every 5 minutes for 20 minutes.